title: MRI of Thiel-embalmed human cadavers.
abstract: OBJECTIVE
  To explain the observed considerable loss of signal and contrast when Thiel-embalmed human cadavers are imaged using clinical magnetic resonance imaging (MRI) sequences, especially those based on spin-echo MRI.
  
  
  METHODS
  All cadavers were imaged with a medical 1.5T scanner using standard MRI sequences. Dual angle B1+ magnitude mapping and electromagnetic (EM) simulations that characterize the radiofrequency (RF) penetration in a male human body model (HBM) were carried out for a range of tissue conductivities.
  
  
  RESULTS
  The EM simulations show that RF penetration issues begin to affect the image quality for values of electrical conductivity as low as 2.6 S/m. The electrical conductivity values of the embalming fluids were found to be within the range of 5-10.6 S/m, thus strongly suggesting that the observed loss in signal and contrast is due to diminished RF penetration inside the cadavers. Furthermore, it was demonstrated that gradient-echo (GRE)-based MRI sequences perform better than spin-echo (SE)-based sequences, as they are less susceptible to imperfections in the flip angle that are inevitably present when imaging Thiel cadavers.
  
  
  CONCLUSIONS
  The diminished signal and contrast observed when imaging Thiel-embalmed human cadavers may be attributed to the high conductivity of the embalming liquids.
authors.affiliation: Institute for Medical Science and Technology, University of Dundee, Dundee, Scotland, UK.
authors.forename: Mariana J
authors.initials: MJ
authors.lastname: Gueorguieva
authors.forename: Desmond T B
authors.initials: DT
authors.lastname: Yeo
authors.forename: Roos
authors.initials: R
authors.lastname: Eisma
authors.forename: Andreas
authors.initials: A
authors.lastname: Melzer
mesh_terms: D002102:Cadaver; D017352:Echo-Planar Imaging / Q000379:methods*; D004615:Embalming / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012680:Sensitivity and Specificity
keywords: RF mapping; Thiel embalmed human cadavers; electromagnetic modeling; flip angle inaccuracy